Show Posts
Pages: [1]
1  Using Arduino / Sensors / Re: multiple HC-SR04 ultrasonic distance sensors on: January 06, 2012, 06:49:32 pm
will a HC-SR04 echo if it wasnt triggered but recieves the signal of another HC-SR04? i think according to the doc, the sensor starts the echo signal right after the triggering and ends it according to the measured distance. so then a sensor that wasnt triggered shouldnt create an echo, no?
2  Using Arduino / Sensors / multiple HC-SR04 ultrasonic distance sensors on: January 06, 2012, 03:09:32 pm

I'd like to use 4 HC-SR04 sensors on my bot using the ultrasonic library. I have two questions regarding it:

1. Timing:
When i use a sensor, it triggers it by stting the trigger pin to high and then waits for the sensor to respond. depending on how long this waittime is, the distance is calculated. now this means, that the execution speed is significantly slowed down by this waiting times - so my question is, whether it's somehow possible to use the HC-SR04 with interrupts instead. and also, whether it's possible to trigger all 4 sensors at once and still get the correct results back, instead of triggering one, waiting for the result, then triggering the next one and so on.

2. Pins:
For each sensor i need a pin for triggering and one to listen to the response. That's 8 pins for the 4 sensors. I was wondering how i can safe on pins. I think it's not a good idea to hook all triggers to a single pin, but would it be possible to connect all sensor responses to a single arduino input pin? if i trigger the sensors after each other it means i know from which sensor the signal is comming from. or could the other sensors be disturbed by the signal created by the currently used sensor?
3  Using Arduino / Programming Questions / Re: arduino software updatable through SD card on: December 22, 2011, 03:34:00 pm sais it can be used to store data in flash memory..
4  Using Arduino / Programming Questions / arduino software updatable through SD card on: December 22, 2011, 02:56:39 pm
Say I have an Arduino Setup with a SD card reader and a LCD/Keypad shield.

And I want to write the software such that i can make updates to the software through the SD card. So, for example, copy some file onto the SD card through the computer, put it into the Arduino SD slot, chose 'update firmware' with the LCD/Keypad shield and then the new version of the software should be loaded onto the arduino memory.

I guess i have to somehow split the program into a basic core and code that gets loaded at runtime from the flasmemory. To read the SD card from the core at startup, check if some certain firmware file is there, copy code over to the flash memory using PROGMEM and then load and infuse the code somehow from the flash memory.

Is this possible? is it possible to compile some sort of library that can be loaded onto the arduino and called into?
5  Topics / Device Hacking / iPhone Camera Module? on: December 14, 2011, 06:23:25 am

iPhone camera modules sell pretty cheap on e-bay.

here for example an iPhone 4 one with 5MP for 15€:

is it feasible to interface such a camera with arduino? Did anyone do so successfully (or for another model..)?

Pages: [1]